Making an RT-11 boot disk

[Allison]

Ethan Dicks wrote:
> On 4/10/07, David Betz <dbetz at xlisper.com> wrote:
>> Thanks again! I have now successfully installed a minimal RT-11 on
>> the RD54 of my PDP-11/73 system and it boots! Now I just have to
>> configure it with the programs I need (like DECUS C).
> 
> Well done.
> 
>> I guess RT-11 uses 512 byte blocks. My RD54 says it holds around 64k
>> blocks. That's about 32mb.
> 
> That's the first partition.
> 
>> What happened to the rest of the 150mb RD54?
> 
> It's still there, lurking.
> 
>> Is it possible to put more than one partition on the drive or
>> to convince RT-11 to use more than 32mb of the disk?
> 
> RT-11 uses, IIRC, 16-bit block pointers... 65536 x 512 bytes == 32MB,
> the largest swath of a big drive it can grab in one chunk.  I've never
> personally run RT-11 with a disk over 32MB, so I don't know how it's
> done, but I know it can be done.  It might or might not depend on what
> version of RT-11 you have.  I *think* if you have MSCP support, you
> always have the ability to have multiple partitions on your large
> drives, but someone with experience on new(ish) hardware should chime
> in.  The largest machine I ever ran at home was an 11/23 with a couple
> of RL drives.  When I did use RT-11 on an 11/73 with a large disk, it
> was under TSX-11, and without the docs in front of me, I'd hesitate to
> quote technique from memory.

You have to use the LD driver.  Myself I use a smaller drive as 32mb for
RT-11 is a very roomy disk.  A Quantum D540(rd52) at 32mb is perfect, they
are also cooler and far more reliable.   Another good choice is an St225
(rd31) at 20mb it's still large for a RT-11 system.

Allison

> You should be able to find what you are looking for in the RT-11 docs
> for versions of RT-11 > 5.4, at least.  Dunno about < 5.4.
> 
> -ethan
>